The proposed project is a competing renewal of the TEETH ("Trials to Enhance Elders' Teeth and Oral Health") study funded by NIDCR (R01 DE012215, 9/30/97 - 7/31/02). This double blind, randomized clinical trial, supervised by a Data and Safety Monitoring Board (DSMB), was designed to provide unequivocal evidence regarding the impact of regular rinsing with a 0.12% chlorhexidine solution on tooth loss in low income, community dwelling older adults. A sample of 1101 people aged 60-75 was recruited between 05/98 and 08/99, with 701 in Seattle, 400 in Vancouver, B.C. (under a subcontract to the University of British Columbia). Random assignment resulted in 550 elders in the active rinse, 551 in the placebo. As of the last DSMB meeting in 07/01, the tooth loss rates in groups A and B were 13 and 16 lost teeth per 1000 tooth-years, respectively (p=0.44). The attrition rate and non-compliance rate were lower than projected and were not dependent on treatment assignment. No treatment-related adverse effects have been identified to date. Mortality rates in both groups are similar, and the most common oral lesion - lichen planus - has a similar prevalence in both groups. Surrogate measures of periodontitis and caries are reported annually to the TEETH DSMB. The purpose of this competing renewal is to complete the data follow-up until 12/04, including following up with dentists who have extracted teeth in these subjects during their enrollment in TEETH. Group comparisons will assess the impact of the low-cost chlorhexidine rinse regimen on 5-year incidence of root and coronal caries, attachment loss, and the true endpoint, tooth loss. Clinical data, radiographs, and health histories will aid in determining reasons for tooth loss, in addition to the impact of rinsing with the active vs. placebo solution. The same research team will continue to monitor, analyze, and conduct the TEETH study at both sites, using the protocol stipulated in the initial application, including the modifications provided by the DSMB. Every indication to date suggests a successful completion of this trial as projected.